Apparatus for smoothing a product, in particular a semi-finished ceramic product

ABSTRACT

An apparatus ( 1 ) for smoothing a product ( 2 ), in particular a semi-finished ceramic product, comprises: an abrasive tool ( 3 ) in the form of an endless belt ( 4 ) which is trained around at least one pair of pulleys ( 5, 6 ), at least one of which is power-driven; the belt ( 4 ) has an active section ( 7 ) and at least one passive section ( 8 ); the active section ( 7 ) removes material from the product ( 2 ), while the passive section ( 8 ) receives a regenerating treatment that restores the abrasive capacity of the tool ( 3 ); drive means ( 20 ) acting on the belt ( 4 ) in such a way as to enable the belt ( 4 ) itself to move in the space surrounding the product ( 2 ); means ( 10 ) for spraying a liquid on the belt ( 4 ), which has liquid absorption properties, said means ( 10 ) being located in the vicinity of the belt ( 4 ) itself; and negative pressure means ( 9 ) associated with the passive section ( 8 ) of the belt ( 4 ) and operating in such a way as to extract the liquid and the materials retained by the belt ( 4 ) and removed from the product ( 2 ) during the smoothing process.

BACKGROUND OF THE INVENTION

This invention relates preferably to ceramics technology for themanufacture of ceramic products by casting a suspension in water of aclayey raw material (known as “slip”) in porous moulds to obtainsemi-finished sanitaryware such as washbasins, bidets and similararticles.

The invention relates in particular to an apparatus for finishing theseproducts by smoothing their surfaces during the manufacturing processwhile they are still in “states” that allow abrasive means to be used onthem with the aid of liquids to facilitate their machinability, that isto say, when they are in the “green” and “leather hard” states.

This specification refers to this particular technology. It will beunderstood, however, that the description is provided purely by way ofnon-limiting example, since the characteristics of the invention aresuch that further, advantageous applications of it are possible insectors other than the reference sector.

The surface smoothing of semi-finished ceramic products obtained by slipcasting is preferably performed when the products are in the “green”state (that is to say, solid but still having a water content of between17% and 20% by weight—and hence still subject to plastic deformation) orin the “leather hard” state (with a water content normally less than13%, where the product, although rigid, can still be worked with a wetsmoothing tool). However, under certain conditions, smoothing can alsobe performed when the product is already in the “dry” state, that is,having a water content normally below 2%.

A prior art apparatus—described in document EP 640.450—comprises afinishing tool that can be automatically regenerated continuously whileworking.

The tool comprises a power-driven endless abrasive belt trained aroundthree pulleys positioned in space in such a way as to subtend the beltto a form closed, three-sided figure comprising an active section, apassive section and a transmission section.

The passive section is associated with a tank containing a liquidthrough which the passive section moves and remains permanently dipped.

The semi-finished product to be smoothed, held by a robot-controlledmechanical manipulator, is suitably oriented in space and moved intocontact with the active belt section which slides tangentially over thesurface of the semi-finished product to remove burs and other surfaceirregularities.

The particles of ceramic material removed are trapped in the materialstructure of the abrasive belt's active section and are washed away whenthe active section moves on to become the passive section and is dippedinto the tank.

The method described above has inherent disadvantages, one of which isthe fact that it involves moving the semi-finished product and keepingthe smoothing apparatus stationary, the apparatus being much lighter inweight than the product.

The negative consequences of this are not difficult to imagine. Theheavy weights that the robot is required to handle are reflected in thehigh cost of installation and in the equally high costs of running andmaintenance, not to mention the extended process times.

Another disadvantage is that smoothing using the method described aboveis relatively easy if the surfaces to be smoothed are convex but, on thecontrary, is considerably difficult, or even impossible, if the surfacesare concave.

Another disadvantage is that the robots must be provided with adifferent end effector for each different product to be manipulated, thewider the range products, the higher the number of different effectorsrequired.

Moreover, the patterns of motion involved in the manipulation of theproduct may be very complicated, which means that the parts of theproduct that come into contact with the robot are subjected to stressthat is not always negligible and are therefore liable to damage.

This makes it problematical to handle relatively large products such asarticles of sanitaryware, which are heavy and fragile, and which cannotbe held suspended in the air without the risk of breaking them.

Yet another disadvantage, connected with the regeneration of theabrasive belt in a tank of water, is that the tank can have only one,predetermined and invariable orientation in space: this placesconsiderable limitations on the versatility of the installation in termsof providing the best operating conditions for the finishing operations.

To overcome the above disadvantages, rotary tools (such as cylindricalsponges) can be used. These tools are rotated while the product(especially “greenware”) is held stationary in a predetermined position.

These tools, too, are not free of disadvantages, however. They have tobe cleaned frequently to restore their effectiveness after just a fewruns, which means their productivity is not very high. Above all, theinherent characteristics of the tools and of the rotary drive systemrequire make it impossible to withhold the material removed from theproducts which ends up being splashed on the surrounding area and on theproducts themselves.

SUMMARY OF THE INVENTION

It is therefore an aim of this invention to provide a finishing andsurface smoothing apparatus which can overcome the disadvantagesinherent in prior art smoothing belts while at the same time offeringthe advantages of rotary tools.

In accordance with the above mentioned aim, this result is achieved by asmoothing apparatus whose technical characteristics may be easilyinferred from the contents of the appended claims, especially claim 1,and any of the claims that depend, either directly or indirectly, onclaim 1.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages of the invention are more apparent from the detaileddescription which follows, with reference to the accompanying drawingswhich illustrate preferred embodiments of the invention provided merelyby way of example without restricting the scope of the inventiveconcept, and in which:

FIG. 1 is a front face view, with some parts shown schematically andothers cut away, of the smoothing apparatus according to the invention;

FIG. 2 is a side view of the apparatus of FIG. 1 ;

FIG. 3 is a scaled-up view of a detail from FIG. 2 illustrating somesignificant parts of the apparatus;

FIG. 4 is a front face view, with some parts cut away in order to betterillustrate others, of another embodiment of the smoothing apparatusshown in the illustrations listed above;

FIG. 5 illustrates the smoothing apparatus of FIG. 4 in a side view withsome parts in cross section and others cut away in order to betterillustrate certain details;

FIG. 6 is a rear face view of the smoothing apparatus of FIGS. 4 and 5;

FIG. 7 illustrates a detail of the apparatus of FIG. 5 in a front faceview and in a partly inoperative configuration;

FIG. 8 shows a cross section of a belt used in the smoothing apparatusof FIGS. 4 to 7;

FIG. 9 is a schematic perspective view, with some parts cut away, ofanother embodiment of the apparatus of FIGS. 1 to 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to FIGS. 1 to 3 of the accompanying drawings, thesmoothing apparatus according to the invention, labeled 1 in itsentirety, is used to smooth a product 2 (illustrated schematically sinceit does not strictly form part of the invention), in particular, asemi-finished ceramic product obtained by casting a liquid mixture(known as “slip” in the jargon of the trade) in a molding cavity formedby at least two parts of a mould.

The apparatus 1 basically comprises an abrasive tool 3 in the form of anendless belt 4 which (in the embodiment illustrated) is trained aroundat least one pair of pulleys 5 and 6, at least one which is power-driven(by a respective motor 5 m), and which defines an active section 7 and apassive section 8 of the belt 4:

the first, active section 7 identifies the part or branch of the belt 4that is designed to remove material from the product 2; while

the second, passive section 8 is designed to receive a continuousregenerating treatment that restores the abrasive capacity of the tool 3making it suitable for smoothing purposes when that section of the belt4 becomes the active section again.

The apparatus 1 also comprises:

drive means 20 acting on the belt 4 in such a way as to enable the belt4 itself to move in the space surrounding the product 2;

means 10, located in the vicinity of the belt 4, for spraying a liquidon the belt 4 itself, which has liquid absorption properties;

suction means 9 associated with the passive section 8 of the belt 4 andoperating in such a way as to remove the liquid and the process wastematerials retained by it, that is to say, the materials removed from theproduct 2 during the smoothing process and retained by the belt 4.

The means 20 enable the apparatus 1 to be associated with a manipulator21, preferably robot-controlled (partly illustrated since it is of knowntype).

The association of the apparatus 1 with a manipulator 21 controlled by arobot or even manually by an operator, enables the belt 4 to move in thespace surrounding the product 2 in such a way as to orient its activesection 7 relative to the lateral surfaces of the product 2 as requiredfor smoothing.

In particular, again with reference to FIGS. 1 to 3, in a firstembodiment, the above mentioned structure 20 may comprise a swingingmounting arm 22 (see arrow F22) pivoted at 22 a to a support 23connected to flanged means 24 for connection to the manual orrobot-controlled manipulator 21.

The lower pulley 6 of the belt 4 is rotatably connected to the first arm22, at the lower end of the first arm 22.

The upper end of the arm 22 is associated with a counterweight 25 forbalancing the center of gravity of the first arm 22 itself, and hence ofthe belt 4: in this way, the belt 4 is kept in a neutral positionalconfiguration independent of the position adopted by the apparatus 1 asa whole. In other words, the belt 4 and the first arm 22 remain in astatic, substantially stationary, configuration, especially duringmovements towards and away from the product 2.

The first arm 22 is also provided with adjustable limit stop and contactmeans 26 acting between the first arm 22 and the support 23 and designedto permit adjustment of at least one stable end position where the firstarm 22 is angularly closest to the support 23 and where movement towardsthe belt 4 is stopped when the belt 4 comes into contact with theproduct 2.

As regards the force of contact which the active section 7 of the belt 4must possess to operate on the product 2, the invention contemplates theprovision of pushing means 100 composed of a cylinder 101 mounted on thesupport 23 and acting on a roller 102 that is keyed to the first arm 22and positioned eccentrically with respect to its pivot point 22 a: inthis way, the active section 7 of the belt 4 may apply a predeterminedcontact force on the product 2, even in combination with the manipulator21, according to the pushing force exerted by the cylinder 101 (seearrow F101) on the eccentric roller 102.

The numeral 103 indicates a block (see FIG. 1) representing controlmeans acting on the cylinder 101 and designed to activate and deactivatethe cylinder 101, when required, deactivation of the cylinder 101,obviously, causing the first arm 22 to return to a neutral position.

The limit stop and contact means 26 are located at two different pointsof the first arm 22 and each consists of a threaded rod 27 protrudingtransversally from the first arm 22 and screwed into a respective hole28 made in the first arm 22.

Each of the rods 27 has an end head 29 designed to come into contact, inuse, with respective zones of the support 23.

The above mentioned lower pulley 6 is connected by its mounting shaft 6a, to the inside of a slot 30 made in the first arm 22 and in such a waythat, when required, it can be moved (arrow F30) to adjust the tensionof the belt 4 by slackening the shaft 6 a from the slot 30 and, ifnecessary, to change the belt 4 itself.

As clearly shown in FIG. 3, the above mentioned upper pulley 5 of thebelt 4 is connected to its drive 5 m which is in turn mounted on abracket 32 protruding from the first arm 22.

As stated earlier, in order to enable the abrasive properties of thebelt 4 to be regenerated continuously while working, the belt 4 is madeof a material that absorbs liquid—for example water—which is sprayed onthe belt 4 by the above mentioned spraying means 10 which the apparatus1 is equipped with.

More specifically (see also FIG. 3), the liquid spraying means 10 arelocated in the vicinity of the belt 4 itself.

In one example embodiment, shown in FIG. 2, the means 10 may be mounteddirectly on contact means 18 (described in more detail below) andcomprise nozzles for spraying liquid on the belt 4.

In particular, the spray means 10 may consist of a plurality of nozzles10 a, fed by a respective source 10 b, positioned upstream of thenegative pressure means 9 relative to a direction of rotation (indicatedby the arrow S) of the belt 4 in such a way that they face a portion ofthe passive section 8 of the belt 4.

As just mentioned, the apparatus 1 also comprises negative pressuremeans 9 which are associated with the passive section 8 of the belt 4and which are designed to remove from the belt 4 the liquid sprayed ontoit by the spraying means 10 together with the process waste materialremoved and retained by the belt 4 during the active stage of thesmoothing process and transferred to the passive stage of the smoothingprocess.

The negative pressure means 9 include, in particular, a roller 11 whichrotates freely about its axis of rotation 15 and which is in direct,tangential contact with the passive section 8 of the belt 4.

The roller 11, cylindrical in shape, is rotatably coupled coaxially witha hollow pin 17 that defines a cavity 12 inside it.

The roller 11 also has a cylindrical outside lateral operating surface11 a provided with a plurality of through holes 11 b designed to allowthe outside and the inside of the cavity 12 to communicate through aslot 17 c formed on the hollow pin 17 in such a way as to face thepassive section 8 of the belt 4.

The lateral surface 11 a of the roller 11 has shoulders 16 having anenveloping shape matching the opposite longitudinal edges of the belt 4.

The cavity 12 inside the hollow pin 17 is designed to suck the liquidand the smoothing process waste material out through the roller 11, thatis to say, through the holes 11 b in the lateral surface 11 a andthrough the slot 17 c; the suction being produced by: the negativepressure created inside the cavity 12 by the fluid connection of thecavity 12 with vacuum generating means 31 m such as, for example, avacuum pump, represented as a block in FIG. 3 since they are entirelyconventional; as well as by the direct connection of the cavity 12 withthe holes 11 b, through the slot 17 c in the pin 17.

In other terms, the roller 11 turns freely together with the belt 4 andwhen the portion of the roller 11 surface with the holes 11 b comes intocontact with the passive section 8 and the holes coincide with the slot17 c, the process waste material is removed from the passive section 8by the suction produced.

More specifically, the roller 11 is held in direct, forced contact withthe belt 4 by contact means 18 which include a mounting arm 18 a andelastic elements 19 interposed between the roller 11 and the first arm22 and which operate in such a way as to compress the roller 11 againstthe belt 4 so as to maximize the effect of the seal and, hence, theeffectiveness of suction.

Obviously, the products sucked into the cavity 12 and consisting, asalready stated, of liquid and process waste, once they reach theinterior of the cavity 12, are then carried by the negative pressurealong a conveyor 31 circuitally connected with the vacuum pump 31 m (seearrow F31 m).

FIGS. 4 to 7 illustrate a second embodiment of the apparatus 1.

In this specific case, the belt 4 mounting structure 20 comprises:

a box-shaped frame 33 equipped at the top of it, with flange means 34for connection to the above mentioned manipulator 21 and mounting theabove mentioned spraying means 10 inside it, the negative pressure means9 acting (in this case) at an arc-shaped passive section 8 of the belt 4passing over the upper pulley 5 that is rotatably mounted inside theframe 33 and equipped with a respective drive 5 m;

a rigid support 35 associated with the box-shaped frame 33 and extendingdownwardly from the latter as far as the bottom end of the lower pulley6 of the belt 4.

The support 35 also has in the middle of it an auxiliary idle wheel 36that is rotatably connected to the support 35 and in bilateral contactwith a protruding internal profile of the belt 4 in such a way as toenable the latter to slide more easily.

The spraying means 10, the negative pressure means 9, the upper pulley 5and the related drive 5 m are mounted on a first member 60 locatedinside the frame 33 and pivoted at end of it and at 60 a to the frame 33itself.

The member 60 is acted upon by tensioning means 61, composed of acylinder 62 located at the bottom of the frame 33, protruding verticallyinside the frame 33 and acting on an idle roller 63 connected, at 63 a,to the member 60 and positioned eccentrically with respect to the pivotpoint 60 a of the member: in this way, moving the member 60 up or down(see arrow F60, FIG. 4) moves the upper pulley 5 in such a way as totension or slacken the belt 4.

The numeral 64 indicates a block (see FIGS. 4 to 7) representing controlmeans acting on the cylinder 62 and designed to activate and deactivatethe cylinder 62, when required and in such a way as to control the forceapplied by the cylinder 62 to the roller 63, thus keeping the tension ofthe belt 4 under control.

As regards the spraying means 10 and the negative pressure means 9, thelatter are made in a portion 37 of the member 60 that is pivoted at 37 ato the member 60 itself, in such a way as to enable the portion 37 torotate between:

a lowered operating position, where the spraying and negative pressuremeans 10, 9 are in contact with the passive section 8 of the belt 4(arrow F37, FIG. 4); and

a raised, non-operating position where the spraying and negativepressure means 10, 9 are away from the upper pulley 5 and from the belt4 in such a way that the latter can be substituted (see arrow F37 a,FIG. 7) while the cylinder 62 is deactivated.

In this case, the negative pressure means 9 (see FIGS. 4 and 7) arecomposed of a closed cylindrical chamber 65 provided with a slit 65 a(see FIG. 7) that can be positioned to face the passive section 8 of thebelt 4 when the portion 37 is in the lowered position.

The negative pressure is generated in the chamber 65 using suitablemeans 65 b which, in this case, purely by way of example, are embodiedby a Venturi unit, partly illustrated in FIG. 7, through which theprocess waste material is removed by suction, channeled into the pipe 65c (see arrow F65 c) and then expelled.

The spraying means 10 comprise two sets of nozzles 10 a made on theportion 37 on opposite sides of the cylindrical chamber 65: the liquidsupply means 10 b are, obviously, activated by one or the other of thesets of nozzles 10 a depending on the rotation direction S of the belt 4and in such a way that the belt 4 is always sprayed before it moves pastthe cylindrical chamber 65: that means the belt 4 can operate in bothdirections of rotation.

Means 38 are provided between the portion 37 and the member 60 forlocking the containing portion 37 in the lowered operating position sothat it can be positioned stably over the belt 4.

The locking means 38 comprise a vertical lever 39 pivoted at one of it,at 39 a, to the member 60 and snappingly engageable, at it its freeopposite end, with a pin 40 that protrudes laterally from the portion 37and that can be positioned near the lever 39 when the portion 37 is inthe lowered operating position.

An elastic element 41 is interposed between the lever 39 and the member60 so as to keep the lever 39 constantly in contact with the pin 40.

In other words, when the portion 37 is lowered towards the belt 4, thepin 40 comes into contact with the rounded head of the lever 39 which inturn withdraws to allow the passage of the portion 37 and of the pin 40,thus extending the elastic element, or spring, 41; once the pin 40 haspassed, the lever 39, under the pulling action of the spring 41, returnsto the advanced position, thereby locking the pin 40 under it and thusholding the portion 37 in place: this keeps the portion 37 correctlypositioned against the passive section 8 of the belt 4, allowing thecylindrical chamber 65 to remove the material from the belt 4 bysuction.

For obtaining the optimum position of the portion 37 at all times,adjustable limit stop means 70 (see also FIGS. 5 and 6) are providedbetween the portion 37 and the member 60: the means 70 comprise a bolt70 a screwed into a threaded through hole made in the portion 37 in sucha way that its lower end comes into contact with a surface of the member60 when the portion 37 is in the lowered position.

Screwing or unscrewing the bolt 70 a thus moves the portion 37 towardsor away from the belt 4, according to the thickness of the belt 4 andits state of wear, and, hence, according to the need to move thecylindrical suction chamber 65 towards or away from the passive section8 of the belt 4.

The belt 4 may have a quadrangular cross section and regular thickness,or a quadrangular cross section and regular thickness with an internalprotruding profile running along the middle of it (see FIG. 8) to guidethe belt 4 more effectively around the drive pulleys.

The apparatus 1 made as described above makes it possible to smooth ageneric product 2 of any shape held stationary while only the tool 3moves.

This offers numerous advantages.

Since the moving part of the apparatus is the tool 3, which isconsiderably lighter than the product 2 (at least when the latter is asemi-finished ceramic product), the robot-controlled manipulatorrequired to drive the tool 3 may be relatively small and inexpensive.

Also, the possibility of orienting the belt 4 quite freely makes itpossible to expose the product 2 not only to the active sections 7 ofthe belt 4 but also to the portions of it, for example, close to thecurved area where the belt 4 moves around the pulleys.

That means the tool 3 can work also on small and/or, if necessary, evenconcave, parts of the surface of the product 2.

Further, the belt 4 is regenerated by a forced suction system that notonly has no influence on the structure of the apparatus 1 but also hasthe advantage of being very effective in removing process waste materialand thus provides high regenerating performance.

Another advantageous aspect of the invention is due to the fact that thetwo drive units described above can be used for a plurality of products2 of different shapes and sizes, with obvious advantages in terms ofversatility because the apparatus 1 is applicable to a wide range ofgeneric products 2.

In the second embodiment described, the special structure of the rigidsupport 35 allows the belt 4 to be positioned even horizontally to beable to work even on parts of the product 2 that are difficult toaccess, which is added to the fact that use of the curved belt sectionat the upper pulley 5 as the regeneration area makes it possible to havetwo active sections of the belt 4 available at all times.

In the first preferred embodiment of the invention as described above,the roller 11 is mounted laterally of the two pulleys 5 and 6 aroundwhich the belt is trained and acts as a tensioner of the belt 4 thanksto the compression it exerts on the passive section 8.

It will be understood, however, that numerous variants of thisembodiment are possible, the easiest one to imagine being that theroller 11 could be integrated into one of the pulleys 5 or 6 aroundwhich the belt 4 is trained, the belt being in this case a Moebius belt(as clearly illustrated in FIG. 9).

The invention described above is susceptible of industrial applicationand may be modified and adapted in several ways without therebydeparting from the scope of the inventive concept. Moreover, all detailsof the invention may be substituted by technically equivalent elements.

1. An apparatus (1) for smoothing a product (2), in particular asemi-finished ceramic product, comprising an abrasive tool (3) in theform of an endless belt (4) trained around at least one pair of pulleys(5, 6), at least one of which is power-driven; and having at least oneactive section (7) and at least one passive section (8); the activesection (7) being adapted to remove material from the product (2) whilethe passive section (8) receives a regenerating treatment that restoresthe abrasive capacity of the tool (3); the apparatus (1) furthercomprising: drive means (20) acting on the belt (4) in such a way as toenable the belt (4) itself to move in the space surrounding the product(2); means (10), located in the vicinity of the belt (4), for spraying aliquid on the belt (4) itself, which has liquid absorption properties;negative pressure means (9) associated with the passive section (8) ofthe belt (4) and operating in such a way as to remove the liquid and theprocess waste materials retained by it.
 2. The apparatus according toclaim 1, wherein the spraying means (10) are nozzles designed to directthe liquid at a precise area of the belt (4).
 3. The apparatus accordingto claim 1, wherein the spraying means (10) are composed of a pluralityof nozzles (10 a) positioned in such a way as to face a portion of thepassive section (8) of the belt (4), upstream of the negative pressuremeans (9) relative to a rotation direction (S) of the belt (4).
 4. Theapparatus according to claim 1, wherein the negative pressure means (9)comprise a cylindrical roller (11) having an internal cavity (12) andexternal lateral surface (11 a) through which at least one hole (11 b)and which delimits a vacuum chamber (12) communicating with the outsidethrough the hole/each hole (11 b); the roller (11) being in directcontact with the passive section (8) of the belt (4).
 5. The apparatusaccording to claim 4, wherein the roller (11) is freely rotatable aboutits rotation axis (15).
 6. The apparatus according to claim 5, whereinthe roller (11) is integrated into one of the pulleys (5, 6) aroundwhich the belt (4) is trained.
 7. The apparatus according to claim 5,wherein the roller (11) is a tensioner of the belt (4).
 8. The apparatusaccording to claim 4, wherein the lateral surface (11 a) has a pluralityof holes (11 b) passing through it.
 9. The apparatus according to claim4, wherein the lateral surface (11 a) of the roller (11) has shoulders(16) that envelope the opposite longitudinal edges of the belt (4). 10.The apparatus according to claim 4, wherein the roller (11) is coaxiallyand freely rotatable on a hollow pin (17) defining the cavity (12); thehollow pin (17) also having a slot (17 c) facing the passive section (8)of the belt (4); the cavity (12) inside the hollow pin (17) beingdesigned to remove the liquid and the smoothing process waste materialby suction from the passive section (8) of the belt (4) through theroller (11), that is to say, through the holes (11 b) in the lateralsurface (11 a) and through the slot (17 c).
 11. The apparatus accordingto claim 10, wherein the hollow pin (17) is acted upon by vacuumgenerating means (31 m) adapted to produce a negative pressure in thecavity (12) in such a way as to remove the process waste material bysuction passing directly from the passive section (8) through the holes(11 b) and slot (17 c) in the pin (17).
 12. The apparatus according toclaim 10, comprising means (18) for keeping the roller (11) in forcedcontact with the belt (4).
 13. The apparatus according to claim 12,wherein the forced contact means (18) comprise a mounting arm (18 a) andelastic elements (19) interposed between the roller (11) and the firstarm (22) and operating in such a way as to apply sufficient compressionbetween the roller (11) and the belt (4).
 14. The apparatus according toclaim 1, comprising a manipulatable structure (20), constituting saiddrive means, which mounts the belt (4) and the negative pressure means(9).
 15. The apparatus according to claim 14, wherein the structure (20)can be manipulated manually by an operator.
 16. The apparatus accordingto claim 14, wherein the structure (20) is associated with a mechanicaland/or robot-controlled manipulator (21).
 17. The apparatus according toclaim 14, wherein the structure (20) comprises a first swinging mountingarm (22) pivoted at (22 a) to a support (23) connected to means (24) forconnection to the manual or robot-controlled manipulator (21); a lowerpulley (6) of the belt (4) being rotatably connected to the first arm(22), at the lower end of the first arm (22); the upper end of the arm(22) being associated with a counterweight (25) for balancing the centerof gravity of the first arm (22) and of the belt (4), in such a way thatthe belt (4) can apply to the active section (7) a predetermined contactforce on the product (2) in combination with the manipulator (21). 18.The apparatus according to claim 17, wherein the first arm (22) isprovided with adjustable limit stop and contact means (26) actingbetween the first arm (22) and the support (23) and designed to permitadjustment of at least one stable end position where the first arm (22)is angularly closest to the support (23) and where movement towards thebelt (4) is stopped.
 19. The apparatus according to claim 18, whereinthe limit stop and contact means (26) are located at two differentpoints of the first arm (22) and each comprises a threaded rod (27)protruding transversally from the first arm (22) and screwed into arespective hole (28) made in the first arm (22); each rod (27) having anend head (29) designed to come into contact, in use, with respectivezones of the support (23).
 20. The apparatus according to claim 17,wherein the lower pulley (6) is connected by its mounting shaft (6 a),to the inside of a slot (30) made in the first arm (22) and in such away that, when required, it can be moved to adjust the tension of thebelt (4) by slackening the shaft (6 a) from the slot (30).
 21. Theapparatus according to claim 17, wherein the upper pulley (5) of thebelt (4) is connected to a respective drive (5 m) which is in turnmounted on a bracket (32) protruding from the first arm (22).
 22. Theapparatus according to claim 17, comprising pushing means (100) composedof a control cylinder (101) mounted on the support (23) and acting on aroller (102) that is keyed to the first arm (22) and positionedeccentrically with respect to its pivot point (22 a) in such a way thatthe belt (4) applies a predetermined contact force on the product (2)according to the pushing force exerted by the cylinder (101) on theeccentric roller (102); control means (103) being provided to act on thecylinder (101) and to activate and deactivate the cylinder (101) whenrequired.
 23. The apparatus according to claim 14, wherein the mountingstructure (20) comprises: a box-shaped frame (33) equipped at the top ofit, with flange means (34) for connection to the manipulator (21) andmounting the spraying (10) inside it, the negative pressure means (9)acting at an arc-shaped passive section (8) of the belt (4) passing overthe upper pulley (5) that is rotatably mounted inside the frame (33) andequipped with a respective drive (5 m); a rigid support (35) associatedwith the box-shaped frame (33) and extending downwardly from the latteras far as the bottom end of the lower pulley (6) of the belt (4). 24.The apparatus according to claim 23, wherein the support (35) isprovided in the middle of it with an auxiliary idle wheel (36) that isrotatably connected to the support (35) and in bilateral contact with aprotruding inside profile of the belt (4).
 25. The apparatus accordingto claim 23, wherein the spraying means (10), the negative pressuremeans (9) and the upper pulley (5) and its drive (5 m) are mounted on afirst member (60) located inside the frame (33), the first member (60)being pivoted at one end of it (60 a) to the frame (33).
 26. Theapparatus according to claim 25, comprising tensioning means (61) actingon the first member (60) and composed of a cylinder (62) located at thebottom of the frame (33), protruding vertically into the frame (33) andacting on an idle roller (63) connected, at (63 a), to the first member(60) and positioned eccentrically with respect to the pivot point (60 a)of the first member (60) so as to allow the member (60) to move in bothdirections in such a way as to move the upper pulley (5), therebytensioning or slackening the belt (4).
 27. The apparatus according toclaim 26, comprising control means (64) acting on the cylinder (62) anddesigned to activate and deactivate the cylinder (62), when required andin such a way as to control the force acting on the roller (63) and thusthe tension of the belt (4).
 28. The apparatus according to claim 25,wherein the spraying means (10) and the negative pressure means (9) aremade on a portion (37) of the first member (60); the portion (37) beingpivoted to the first member (60) at (37 a) in such a way as to enablethe entire portion (37) to rotate between a lowered operating position,where the spraying and negative pressure means (10, 9) are in contactwith the passive section (8) of the belt (4), and a raised,non-operating position where the spraying and negative pressure means(10, 9) are away from the upper pulley (5) and from the belt (4). 29.The apparatus according to claim 28, wherein the negative pressure means(9) are composed of a closed cylindrical chamber (65) formed in theportion (37) and provided with a slit (65 a) that can be positioned toface the passive section (8) of the belt (4) when the portion (37) is inthe lowered position; the vacuum being generated inside the chamber (65)by respective means (65 b) which enable the process waste material to bechanneled out by suction through a pipe (65 c).
 30. The apparatusaccording to claim 28, wherein the spraying means (10) comprise two setsof nozzles (10 a) made on the portion (37) on opposite sides of thenegative pressure means (9); each set of nozzles (10 a) being connectedto liquid supply means (10 b) that can be individually activated inaccordance with the rotation direction (S) of the belt (4) and in such away that the belt (4) is sprayed before it moves past the negativepressure means (9).
 31. The apparatus according to claim 28, whereinmeans (38) are provided between the portion (37) and the first mountingmember (60) for locking the portion (37) in the lowered operatingposition so that the negative pressure means (9) and the spraying means(10) can be positioned near the passive section (8) of the belt (4). 32.The apparatus according to claim 31, wherein the locking means (38)comprise a vertical lever (39) pivoted at one end of it, at (39 a), tothe member (60) and acting at it its free opposite end on a pin (40)that protrudes laterally from the portion (37) and that can bepositioned near the lever (39) when the portion (37) is in the loweredoperating position; an elastic element (41) being interposed between thelever (39) and the member (60) so as to keep the lever (39) constantlyin contact with the pin (40).
 33. The apparatus according to claim 32,comprising adjustable limit stop means (70) interposed between theportion (37) and the first member (60) and designed to enable theportion (37), when in the lowered position, to be positioned correctlyrelative to the belt (4); said means (70) comprising a bolt (70 a)screwed into a threaded through hole made in the portion (37) in such away that its lower end comes into contact with a surface of the member(60) when the portion (37) is in the lowered position.
 34. The apparatusaccording to claim 1, wherein the belt (4) has a quadrangular crosssection and regular thickness.
 35. The apparatus according to claim 1,wherein the belt (4) has a quadrangular cross section and regularthickness with an internal protruding profile running along the middleof it.
 36. The apparatus according to claim 1, wherein the belt (4) isin the form of a “Moebius” belt trained around the two pulleys (5, 6).